diff --git a/Lib/posixfile.py b/Lib/posixfile.py
index b16b892..589510d 100644
--- a/Lib/posixfile.py
+++ b/Lib/posixfile.py
@@ -107,7 +107,7 @@
         return posix.fdopen(fd, self._file_.mode)
 
     def flags(self, *which):
-        import fcntl
+        import fcntl, os
 
         if which:
             if len(which) > 1: